This invention pertains to eyeglasses having telescopic lenses, particularly binoculars which are mounted directly on the eyeglass frame.
Binoculars and hand telescopes are well known in the prior art. However these devices require the user to manually raise them to his eyes and hold them there for viewing. Devices which combine eyeglasses and telescopic lenses are also known in the prior art. U.S. Pat. No. 3,273,456 to Feinbloom discloses a pair of bifocal loupes for use on close up work such as surgery or assembly work with miniature parts. In Feinbloom the lenses of regular eyeglasses are adapted to receive special telemicroscopic lenses. The special lenses are set in the regular eyeglass lenses at their bottom and tilted downwardly.
U.S. Pat. No. 2,389,428 to Glasser also discloses a pair of eyeglasses in which the ordinary lenses are adapted to receive telescopic lenses. The device in Glasser is specifically designed for viewing objects in the distance from the viewer. As in Feinbloom the telescopic lenses are set directly into the ordinary eyeglass lenses.
Several problems are encountered with the Feinbloom and Glasser devices. The connection between the ordinary eyeglass lenses and the telescopic lenses tends to be weak, particularly where the eyeglass lenses are very thin as in non-prescription sunglasses. Thus, the devices tend to be fragile. Also, the thickness of the eyeglass lenses limits the size of telescopic lenses that can be used in the devices. Very thin lenses will not support large telescopic lenses. The telescopic lenses also interfere with vision through the directly adjacent part of the eyeglass lenses. Consequently, not only is the field of vision blocked but part of the field covered by the ordinary lenses is wasted.
U.S. Pat. No. 2,024,322 to Wittig discloses goggles which are fitted with telescopic lenses. In Wittig the telescopic lenses extend downwardly from the goggle frame into the non-prescription goggle lenses causing the goggle lenses to be irregularly shaped and also blocking the wearer's field of vision.